1. The Field of the Invention
The present invention relates to a semiconductor device, and more particularly to a semiconductor device which can be driven at a high speed as an inverter circuit.
2. The Technical Background of the Invention
Taking the case of inverter circuits, so called C-MOS (Complementary Metal-Oxide-Semiconductor) inverter circuits are well known. The C-MOS inverter circuit is comprised of a pair of field effect transistors (FETs) comprising a P-channel MOS-FET and an N-channel MOS-FET.
The C-MOS inverter circuit has the advantage that the output voltage is precisely determined because it is completely equal to the reference power supply voltage, but has the drawback that the driving capability is not large.
In view of this, another circuit with enhancement of driving capability is proposed, which is called "Bi-CMOS circuit" constituted by combining a pair of bipolar transistors with a C-MOS circuit.
However, the Bi-CMOS circuit has the opposite relationship in connection with the advantage and drawback with the C-MOS circuit. Namely, with the Bi-CMOS circuit, the output voltage is not precise.